The research traditions concerned with phonetic perception and word recognition have mostly developed independently, and this separation poses problems for extending these research traditions to cochlear implant patients; cochlear implants directly affect sensory stimulation, but their functional significance lies in their ability to enable the Precognition of spoken words. In addition, the success of speech perception through cochlear implants challenges the current understanding of phonetic perception in that many of the acoustic cues that have been thought critical to phonetic perception are not available to cochlear implant users. The proposed studies test late-deafened adult cochlear implant users, with the aim of investigating the link between phonetic perception and word recognition. Study 1 will collect phoneme and word identification responses, and test the hypothesis that individual differences in word recognition can be accounted for by the interaction of phonetic perception and the distribution of words in the lexicon. Study 2 will collect word identification, phonetic discrimination, and phonetic similarity judgments, and test the hypothesis that increases in perceptual sensitivity at phoneme boundaries facilitate word recognition. The long-term objective of these studies is to produce a cognitive model that explains the relationship between phonetic perception and word recognition, and can account for the ability of individuals to recognize speech through diverse sources of sensory information. The results of these studies would enable the development of clinical tests to assess the levels of perceptual and cognitive processing that limit or enhance word recognition abilities in individual patients.